package fristphase.day9_22;

public class StringBuilderDemo {
    public void run(int a){
    }



    public static void main(String[] args) {
        StringBuilder builder1 = new StringBuilder();
        StringBuilder builder2 = new StringBuilder("abc");
        String str = "abc";

        StringBuilder builder3= new StringBuilder(str);
        String str2 = builder3.toString();

        System.out.println(builder3);//默认添加toString
        System.out.println(str2);

        System.out.println(builder3.equals(str2));//默认调用Object的 ==
        System.out.println(str2.equals(builder3));
        System.out.println(str2.contains(builder3));
    }
    class StringDddemo{
        public void run(int a ,int b){

        }
    }

}
class StringDdemo extends StringBuilderDemo{
    public void run(int a){

    }
}
